The Future of Smart Technology

Concrete ‘Nest’ Saves Energy in the Form of Heat for Later Use

Energy storage advancements will become an important enabler for communities transitioning to cleaner methods of energy production, according to EnergyNest CEO Christian Thiel. EnergyNest is an energy storage system. It completed its first pilot installation at Masdar Institute’s Solar Platform, in Abu Dhabi, United Arab Emirates in the second half of 2015. The pilot installation includes two 500 KWh thermal energy storage “nests” showcasing EnergyNest’s modular solid-state thermal energy storage (TES) system.

“Energy storage is extremely important these days. Energy storage enables a more efficient integration of renewable energies,” Thiel said, speaking at the recent Sustainable Innovation Forum in Paris. “For example solar and wind: a lot of times you have the situation where there’s lot of energy production from those sources but no demand or very little demand. In order to harvest the full potential of these renewables, energy storage is the key to success.”

He said that current grids operating with renewable energy sources rely on conventional power plants as a base load, or as a “strategic reserve,” in order to supply power to the grid when the wind or sun isn’t cooperating. “If we have efficient storage mechanisms and technology, we don’t need the strategic reserve anymore,” he said. “We can abolish a lot of these conventional energy production facilities.”

Energy storage essentially enables energy to be time-shifted and later accessed when needed. “It allows us to close the loop on a lot of energy-intensive industries,” Thiel said. He added that 50% of energy demand is actually for heat, “and there are a lot of heat producing and heat consuming industries.”

In the Masdar pilot, two nests are connected to a solar facility. The TES system stores excess solar-derived energy as thermal energy during the day and then uses the thermal energy to power a turbine once the sun has gone down. The modular design of the nest enables deployment to be tailored to each specific energy-generating facility.

The nests are built out of special concrete with thermal properties, named “heatcrete,” which prolongs the life of each nest. Heatcrete offers 70% higher thermal conductivity and around 15% higher heat capacity than other TES-specific concretes. The nests are designed to store energy for around 3 hours.

(photo courtesy EnergyNest)

Applications include TES for concentrated solar power (CSP) plants, and can be used for a range of heat transfer fluids (HTF) thermal oil, water, steam, compressed gases and potentially two-phase HTFs such as water/steam in phase transition.

CSPs are used often in industrial applications including electricity production, seawater desalination, process steam generation and enhanced oil recovery.

EnergyNest can also be used for other fluctuating renewable energy systems, including wind and PV solar.